JP2012508990A - Optical radiation system according to polariton mode with electrical injection of quantum wells - Google Patents

Abstract

  The present invention comprises an optical cavity (10) having at least one optical mode, at least one transmissive reflector (12), and a first set (20) of quantum wells (21, 22). A light (2) radiation system comprising an optical cavity (10) comprising electrical injection means (31, 32, 33) of the quantum well (21, 22) of the first set (20) Regarding (1). The quantum wells (21, 22) of the first set (20) are arranged such that at least one of their electronic resonances is a strong coupling system with the optical mode of the optical cavity (10). And is arranged to emit light (2) according to the exciton-polariton mixed mode. In this system (1), the optical cavity (10) is a quantum well (41, 42, 43, 44, 45) arranged outside the direct range of the electrical injection means (31, 32, 33). ) In which at least one of their electronic resonances is strong with the exciton-polariton mixed mode of the optical cavity (10). Arranged in relation to the quantum wells (21, 22) of the first set (20) as in a coupled system.

Description

  The present invention relates to a light emission system according to a polariton mode with electrical injection of quantum wells.

  The present invention relates to the field of semiconductor light sources using a quantum well structure to obtain a “polariton laser” type effect.

  More specifically, an optical cavity having at least one optical mode, the reflector having at least one transparency, a first set of quantum wells, and the electricity of the first set of these quantum wells The invention relates to a light emitting system comprising an optical cavity comprising a mechanical injection means. The first set of quantum wells is arranged such that at least one of their electronic resonances is in a strong coupling system with the optical mode of the optical cavity and emits light according to the exciton-polariton mixed mode. ing.

  A semiconductor laser is used to generate a monochromatic intense light beam. They are excited with a current circulating in the PN junction, which can be filled with electrons on one side of the optical cavity and holes on the other side. The light beam is generated by recombination of holes and electrons at the junction interface. The operation of the laser is performed by realizing an inversion distribution state in which light emission by electron-hole pair recombination is larger than absorption by generation of electron-hole pairs. This state partially determines the operating threshold of the semiconductor laser, i.e. the minimum density of current circulating in the junction, so that the laser operates. These lasers have the disadvantage of having a fairly high emission threshold, which results in energy loss due to heat and in some cases making it very difficult to obtain the laser effect. Rather, it will be impossible.

  The polariton laser can overcome such a threshold problem. This is based on the principle of Bose-Einstein condensation on exciton-polaritons which are quasiparticles of exciton-photon type existing in a planar microcavity in a strongly coupled system. This device is usually called a “laser” because it emits a light beam comparable to that of a laser. However, this is based on a different principle of operation: exciton-polariton condensation rather than on the emission of excited photons. Thus, the population inversion associated with the threshold in a conventional laser need not be satisfied in a polariton laser that essentially makes the conventional laser a laser with a very low threshold. In addition, this allows it to be integrated into a microcircuit, which can extend the battery life of portable devices. The principle of operation of a polariton laser was first proposed in the document "Phys. Lett. A 214; 193, 1996", for example, the document "Phys. Rev. Lett. 101, 146404 (2008)" Since then, it has been studied in many papers.

  In order to realize a commercially viable polariton laser, it is necessary to produce an electrically injected polariton laser that has never been done before. And it preferably operates at room temperature. This second aspect is described in the literature “Phys. Rev. Lett. 98, 126405 (2007)”, “Phys. Rev. Lett. 101, 406409 (2008)” and “Appl. Phys. Lett. 93”. , 051102 (2008) ", semiconductors having excitons that are stable at room temperature, such as GaN-based materials, are used.

  As described in the document “Phys. Rev. Lett. 101, 406409 (2008)”, it is possible to realize a microcavity in which an active layer is formed of a volume material in which a polariton laser effect is observed under optical excitation. According to another solution, with respect to the threshold obtained for the body structure, it is possible to realize a microcavity with an active layer composed of quantum wells, which can be reduced in principle by a multiple of ten. it can. The quantum well has a planar structure that can confine the movement of electrons and holes according to a certain direction in space, and can leave these movements free in the other two directions. This confinement is discontinuous, giving rise to an energy band whose energy values also follow the quantum well dimensions, as well as the intrinsic properties of the material in which the quantum well is contained. Quantum wells may be manufactured by epitaxy, in particular using molecular beams or chemical vapor deposition.

  Other particles such as excitons may be affected by the quantum well in a similar manner. Depending on the choice of shape and the material containing the quantum well, electrons, excitons, holes and other energy levels can be defined. These particles move between energy levels and as a result emit and absorb photons with specific energies.

  The quantum well polariton structure is described in EP 1729383 and EP 1813981. In the latter, the radiation system comprises a first Bragg reflector, two semiconductor layers surrounding the quantum well, and finally a substrate on which a second Bragg reflector is deposited. The whole forms an optical microcavity in which quantum wells are arranged. The microcavity so formed may spatially arrange polaritons and may include at least three discrete energy levels for the polaritons.

  Another structure is described in US Pat. No. 5,877,509. In this specification, the light emission system includes a resonant optical microcavity, a single quantum well, and a means of resonant conduction. The optical cavity includes two Bragg reflectors including one transmissive Bragg reflector, N-doped and P-doped regions, and an undoped gap region. The quantum well is disposed inside the optical cavity so as to provide at least one energy level of electrons, excitons, holes, and polaritons. Polariton energy levels are obtained when the photon energy is sufficiently close to the energy of the exciton energy level. Light emission systems based on polariton states based on microcavities with multiple quantum wells are described in the literature "Appl. Phys. Letters 92, 061107, 2008", "Phys. Rev. B 77, 113303, 2008". , "Phys. Rev. Letters 100, 136806, 2008" and "Nature 453, p. 372, 2008".

  Although the light emitting diode type function can be realized by the structure described in the above document, the polariton laser effect cannot be obtained. In order to obtain the polariton laser effect, it is necessary to use a structure including multiple quantum wells coupled to each other by the polariton mode. As a result, the coupling between light and matter is maximized, and Polariton's Bose-Einstein condensation is promoted. The main addition of such a polariton laser effect is obtained using a GaAs-based material having a structure containing 12 quantum wells under optical excitation (published in the document “Science 316, 1007, 2007”). ), Obtained using a CdTe-based material having a structure containing 26 quantum wells (published in the document “Nature 443, 409, 2006”) and having a structure containing 93 quantum wells. It was obtained using a GaN-based material having (published in the literature “Appl. Phys. Lett. 93, 051102, 2008”). However, increasing the number of wells suffers from the disadvantage that it becomes difficult or even impossible to electrically inject wells.

  Problems arise with the electrical injection of quantum wells. Indeed, on the one hand, efficient and uniform implantation requires a small number of quantum wells in the active region. This can be explained by the fact that electrons arrive on one side and holes arrive on the other side. Since the latter must pass through all the quantum wells to combine, the injection becomes even more difficult if there are multiple quantum wells between electrons and holes.

  In addition, for marketing it is highly desirable to implement components that operate at room temperature. As mentioned above, the most advanced solution is to use a planar microcavity realized with a wide gap semiconductor such as the GaN family. In this type of structure, a polariton laser effect was added under optical excitation. Furthermore, by using gallium nitride, ultraviolet light of about 350 nanometers is emitted in a wavelength band where the realization of a semiconductor laser remains difficult to understand.

  When using a GaN group material, the hole mobility is much smaller than the electron mobility, so the problem of uniformity of electrical injection is very important. Typically, it is difficult to efficiently inject a number of quantum wells of several units or more. On the other hand, polariton lasers must contain many quantum wells, as described above. In a structure having a quantum well of GaN, the polariton laser effect at 300K was added alone to a structure containing 67 quantum wells (references “Appl. Phys. Lett. 93, 051102”). , 2008 ”).

European Patent No. 1729383 (Publication date: December 6, 2006) European Patent No. 1813981 (Publication date: August 1, 2007) US Pat. No. 5,877,509 (Publication date: March 2, 1999) US Patent Application Publication No. 2007/003697 (Publication date: January 4, 2007)

Phys. Lett. A 214, 193, 1996 Phys. Rev. Lett. 101, 146404, 2008 Phys. Rev. Lett. 98, 126405, 2007 Phys. Rev. Lett. 101, 406409, 2008 Appl. Phys. Lett. 93, 051102, 2008 Appl. Phys. Letters 92, 061107, 2008 Phys. Rev. B 77, 113303, 2008 Phys. Rev. Letters 100, 136806, 2008 Nature 453, 372, 2008 Science 316, 1007, 2007 Nature 443, 409, 2006

  This contradiction between electrical injection, which requires a small number of wells, and the polariton laser effect, which requires the maximum number of wells. The shape used in is no longer usable.

  Thus, even with prior art solutions, it is not possible to realize an efficient system for emitting strong monochromatic light according to the polariton mode by electrical injection of quantum wells.

  The object of the present invention is to insert a sufficient number of quantum wells into the optical cavity to observe the polariton laser effect, and to insert a specific array into the optical cavity that can be efficiently electronically excited in this structure. Is to overcome this technical problem. Of all the inserted quantum wells, only a small part is arranged for electrical injection, and in these wells, the injection occurs in good condition. The other parts of the set of quantum wells are arranged so that this electrical injection is not performed directly. Nonetheless, all wells are associated with a strong coupling system, and the electrically injected wells are optically coupled to other wells by the presence of extended polariton modes in the microcavities.

  Then, polariton mode photons related to all the quantum wells are emitted from the injected quantum well. These photons are absorbed by quantum wells that are not directly excited. The process of emitting photons by injected wells and the subsequent processes absorbed by other wells are very fast in strongly coupled systems and two orders of magnitude shorter than in weakly coupled systems. This is the polariton effect. With such a technique, polaritons can be efficiently injected into a microcavity having a multiple quantum well that is strongly coupled to the optical mode.

  Polariton condensation in the lowest energy state is greatly facilitated when the number of strongly coupled quantum wells is large. Therefore, according to the present invention, polaritons can be electrically injected into this type of structure. The spontaneous radioactive decay of the polariton condensate results in the emission of a strong monochromatic light beam, that is, the radiation enabled by the finite transparency of one reflector.

  Finding a method that utilizes the above-mentioned strong coupling system necessary for obtaining the polariton effect is an approach to the solution. And a very small number of wells are used when using this coupled system to bring about interaction between an electrically injected quantum well and an uninjected quantum well to obtain photon emission according to the polariton mode. Clearly, the remaining wells can be photoexcited by photon absorption, and these wells re-radiate photons directly following the same polariton mode after photoexcitation. became.

  This approach is even more inventive in the sense that it cannot be applied to conventional lasers. Originally, a well that is not electrically excited cannot reach an inversion distribution. They simply absorb light and disrupt the laser effect. On the other hand, for polariton lasers, light absorption is exactly what we are looking for, and it is used to couple excited wells and wells that are not electrically excited.

  In view of this objective, the present invention provides an optical cavity having at least one optical mode for the purpose, wherein the reflector has at least one transparency, a first set of quantum wells, and the first A set of light emitting systems comprising an optical cavity with electrical injection means for these quantum wells. The first set of quantum wells are arranged such that at least one of their electronic resonances is a strong coupling system with the optical mode of the optical cavity and emits light according to the exciton-polariton mixed mode. Yes. In this system, the optical cavity further comprises a second set of quantum wells arranged outside the direct range of the electrical injection means, the second set comprising at least one of their electronic resonances. One is arranged in relation to the first set of quantum wells so that one is in a strong coupling system with the exciton-polariton mixed mode of the optical cavity.

  Here, the person skilled in the art does not directly inject the second set of quantum wells directly, but couples photons emitted by the first set of quantum wells by coupling with the polariton mode. It will be understood that it just absorbs and re-radiates.

  One skilled in the art will also appreciate that the emission of photons out of the cavity, and hence the generation of a monochromatic intense light beam, is due to spontaneous radiative decay of polariton condensation.

  This solution advantageously combines the acquisition of strongly coupled systems and the formation of polariton modes with the original placement of quantum wells. By emitting photons according to the polariton mode, wells that are not electrically injected can be photoexcited by absorbing these photons and re-emit the latter according to the same polariton mode. Then, a system including a resonant optical cavity into which a plurality of quantum wells are inserted is obtained, and all quantum wells participate in the polariton effect so as to obtain a considerably high quantum effect. Furthermore, the small number of electrically injected quantum wells is advantageous for obtaining a polariton laser effect by reducing screening and phase shift phenomena in wells that are not electrically injected.

  According to a particular embodiment, the light is emitted as a directional monochromatic light beam constituting a so-called “polariton laser”.

  More preferably, the first set includes less than 5 quantum wells. As a result, since a small number of wells are implanted, it is possible to perform electrical injection uniformly.

  More preferably, the first set includes a number of quantum wells substantially less than the number of quantum wells of the second set. In this way, the second set of these quantum wells are strongly coupled to the first set of quantum wells (which are electrically injected), so that such a number of wells is used. The polariton laser effect obtained in this way becomes even more substantial.

  More preferably, the first and second sets of quantum wells are identical.

  The optical cavity includes a bottom reflector and an upper reflector disposed at the lower and upper ends of the optical cavity, respectively. The upper reflector is transmissive so that light emitted by the system passes through the upper reflector.

  According to another particularly advantageous embodiment, the reflector of the optical cavity is a Bragg reflector, which has the advantage that very little optical loss is generated.

  According to certain embodiments, the optical cavity includes a P-type doped region and an N-type doped region.

  In the latter case, according to certain embodiments, the optical cavity includes an undoped gap region disposed between the N-type doped region and the P-type doped region, respectively.

  In this case, the quantum wells of the first set and the second set are arranged as follows. The first set of quantum wells is disposed between the gap region of the optical cavity and the P-type doped region, and the second set of quantum wells is connected to the N-type doped region of the optical cavity. Located between the bottom reflector.

  Thus, only the first set of quantum wells is between the N-type doped region and the P-type doped region, that is, between the regions where electrical injection is generated. The second set of quantum wells is not within these regions and is therefore not electrically excited. The first set of wells that are electrically excited produce such exciton-polaritons. Here, the first and second sets of wells are equally related. That is, photons emitted by the first set of wells are absorbed by the second set of wells before exiting the optical cavity and then re-emitted several times.

  According to a particular embodiment, the means for injecting includes at least one set of electrical contacts connected to a source of current.

  In the latter case, according to one particular embodiment, one contact of a set of electrical contacts of the means of implantation is fixed to the N-type doped region and the other contact is fixed to the P-type doped region. The

  According to certain embodiments, the optical cavity is deposited on a substrate. Thereby, the whole latter cavity can be manufactured.

  More preferably, the optical cavity is a plane.

  More preferably, the optical cavity is arranged such that the light emitted by the system is perpendicular to the transmissive reflector of the optical cavity. This effect may be obtained by having a planar optical cavity in which all components are flat and parallel to each other.

  According to a particular embodiment of the system, the first and second sets of quantum wells are composed of a material consisting of the gallium nitride group. Thereby, polariton light belonging to the ultraviolet region of about 350 nanometers can be emitted.

A better understanding of the present invention can be obtained when the detailed description of the non-limiting example embodiments is read in conjunction with the respective drawings.
1 is a diagram of a light emission system according to certain embodiments of the present invention. FIG. It is a figure which shows the motion of an electron and a hole inside the light emission system which concerns on this invention.

  As shown in FIG. 1, a system 1 for emitting light 2 according to a particular embodiment of the invention comprises a substrate 3 and an optical cavity 10. It is designed to operate at a specific radiation wavelength.

  In this embodiment, the system comprises two electrically injected quantum wells 21 and 22 and five uninjected quantum wells 41-45. This choice of the number of wells is clearly depicted in the figure. Thus, those skilled in the art will be able to select a more appropriate number of quantum wells. In particular, a number of less than 5 can be selected for implanted wells. In addition, the number of wells that are not implanted is obviously selected to be larger, and in the case of a structure having a quantum well of GaN, it can be as many as 60. Those skilled in the art will just note that a large total number of quantum wells favors the polariton laser effect.

  The system may be obtained according to molecular beam epitaxy technology on the substrate 3, which is well known to those skilled in the art. As a structure realized on the basis of GaN, a suitable substrate may be GaAs or sapphire.

The optical cavity 10 has at least one polariton mode corresponding to the emission of light due to spontaneous radiative decay of polaritons, which is made possible by one of the two reflectors having finite transparency. Resonant light microcavity. The cavity according to the present embodiment includes two Bragg reflectors 11 and 12, first and second regions 13 and 15 doped N-type and P-type, undoped gap region 14, and quantum wells 21 and 22, respectively. 20, injection means 31 to 33, and a second set 40 of quantum wells 41 to 45. The two Bragg reflectors 11 and 12 are disposed below and above the cavity, respectively. The bottom reflector 11 is, for example, a configuration in which Al _0.85 , In _0.15 N and AlGaN are alternately layered, and its implementation is described in, for example, US Patent Application Publication No. 2007/003697. Yes. Alternatively, Al _0.58 Ga _0.32 N and Al _0.20 Ga _0.80 N are alternately layered. For example, the upper reflector is composed of SiO ₂ and SiN dielectric layers alternately. These alternating layers are indicated in FIG. 1 by successive white and black bands. The thickness of each of the layers is equal to ¼ of the wavelength of emitted light 2.

  These two reflectors 11 and 12 are designed to reflect the light at the emission wavelength of the laser. The upper reflector 12 further has the property of allowing the light 2 emitted from the system to pass through the latter so that it can exit the latter. The reflector having transparency here means a reflector having a finite transparency so that a part of the emitted light can pass through the reflector.

  These Bragg reflectors have the advantage that little energy loss occurs. Nevertheless, according to other embodiments, these Bragg reflectors 11 and 12 may be considered to be replaced by other types of reflectors.

  Between the bottom Bragg reflector 11 and the top Bragg reflector 12, the optical cavity 10 includes a set of intermediate layers. These layers comprise the second set of quantum wells 41-45, the N-type doped region 13, the undoped gap region 14, the first set of quantum wells 21 and 22, and the P-type doped region 15. It is continuous.

  All layers and elements in the system are preferably planar and parallel to each other. The output light 2 will also be emitted in a direction perpendicular to the reference plane of the system.

  The N-type doped region 13 is composed of an N-type doped AlGaN layer. Similarly, the P-type doped region 15 is composed of a P-type doped AlGaN layer. The undoped gap region 14 is constituted by an opening made in the AlInN layer. The current generated by the means of injection and passing through a part of the cavity can be passed through this opening. The remaining portion 16 of the AlInN layer forms a tunnel that manipulates electrons and holes for their movement when current is generated.

  The first and second sets of quantum wells are composed of a GaN / AlGaN mixture containing 20% aluminum, and their thickness should be as small as several atomic layers. By this aluminum ratio, it is possible to maintain a strong oscillator force against excitons and to have a strong coupling system.

  Those skilled in the art will be able to implement regions 13 and 15 in other suitable materials or alloys as well as the above quantum wells without departing from the scope of this patent. In particular, other mixtures such as GaN / InGaN may be realized using gallium nitride to realize the quantum well. Gallium nitride actually has the characteristics of blue emission or ultraviolet radiation. Mixtures based on gallium arsenide such as AlGaAs / GaAs may also be used. In particular, other materials may be selected according to the desired emission wavelength. Other shapes may be considered.

  Furthermore, the quantum wells may be similar or different. In particular, they may have different shapes and may be realized using different materials.

  According to other embodiments, the quantum well may be in the form of quantum wires and quantum dots. Note that confinement by quantum wires, quantum wells, and quantum dots is performed in one, two, and three dimensions in space, respectively. Those skilled in the art are well aware of techniques for manufacturing such quantum structures.

  The injection means 31 to 33 are constituted by several electrical contacts that are powered by the generator 33. The voltage value supplied by such a generator is about 1.6-1.8 volts, and the current passing through the optical cavity 10 is thus dependent on the dimension of the surface of this cavity. These electrical contacts operate in pairs (a pair of 21a and 22a and a pair of 21b and 22b). For each pair, one contact 21a (or 21b) is fixed to the N-type doped region 13, thus referred to as contact N and the other contact 22a (or 22b) is fixed to the P-type doped region. And are thus referred to as contacts P. Thus, by generating a current between two contacts of the same pair, electrons and holes are transposed in opposite directions. As shown in FIG. 2, electrons are transferred from contact N to contact P (arrow 51), and holes are transferred from contact P to contact N (arrow 52).

  Each layer and means of implantation are arranged to allow electrical injection into the first set of quantum wells 21 and 22. The second set of quantum wells 41-45 is not electrically injected in this manner. Furthermore, the first set of quantum wells is arranged such that at least one of their electronic resonances is a strong coupling system with the optical mode of the optical cavity and emits light according to the exciton-polariton mixed mode. ing. This arrangement of quantum wells 21 and 22 is defined in relation to electrical injection means. That is, the quantum wells 21 and 22 are disposed between the two electrical contacts of the pair of electrical injection means, so that photons can be emitted according to the polariton mode of the cavity.

  As current passes through the first set of quantum wells, electrons / excitons and holes become concentrated in these wells. The electronic / exciton resonance of each of these wells then occurs in a strongly coupled system that is coupled to one of the confined polariton modes of the cavity. This strong coupling then results in quasiparticles called exciton-polaritons. These quasiparticles are emitted according to the polariton mode of the cavity.

  The second set of quantum wells 41-45 are arranged outside the direct range of action of the electrical injection means, and for the first set of quantum wells, at least one of their electronic resonances is The optical cavity 10 is arranged so as to be in a strong coupling system with the exciton-polariton mixed mode. Thus, the second set of quantum wells 41-45 will re-radiate after absorbing the photons emitted by the first set of quantum wells according to the polariton mode of the optical cavity. Indeed, the quantum well is arranged outside the injection zone defined by the electrical contacts 21a and 22a which are the means of injection. In addition, the quantum wells 41 to 45 participate in the same polariton mode as the quantum wells 21 and 22. Thus, these quantum wells 41-45 will absorb photons emitted by quantum wells 21 and 22 according to the polariton mode. And the second set of these quantum wells will condense excitons and then emit them in the form of photons according to the same polariton mode of the cavity.

  If the system is planar and all the elements comprising it are parallel to each other, the resulting light emission from the exciton-polaritons will be on the upper surface of the cavity, i.e. the upper Bragg reflector 12. It will happen perpendicular to the top surface.

  As for the light emission in the polariton mode, the latter has nonlinear dependence on the intensity of the injection (or excitation) current.

  The light emission system according to the present invention can obtain very high quantum efficiency, which is defined as the ratio of the number of photons emitted in a given direction to injected electrons or charge carriers. .

  The system may be used in many applications, for example in applications for optically storing data, in particular for DVD players. In the latter case, the memory capacity can be increased by using a system having a quantum well in gallium nitride GaN that emits ultraviolet rays.

  Although the motor plays a substantial role in consumption, the consumption in the device is reduced by reducing the threshold value, and its use in a portable system (portable computer) that wants to make the battery last longer can be expected.

  Finally, another application that may be considered may be to integrate such a polariton laser system on a microcircuit where the problem of heat dissipation is critical.

  The embodiments of the present invention described above are provided by way of illustration and are in no way limiting. Those skilled in the art will appreciate that other different embodiments of the present invention may be implemented without departing from the scope of the patent.

Claims (16)

An optical cavity (10) having at least one optical mode,
At least one transmissive reflector (12);
A first set (20) of quantum wells (21, 22);
An optical cavity (10) comprising electrical injection means (31, 32, 33) for the quantum wells (21, 22) of the first set (20);
The quantum wells (21, 22) of the first set (20) are
At least one of the electronic resonances is arranged to be a strong coupling system with the optical mode of the optical cavity (10), and emits light (2) according to the exciton-polariton mixed mode. Has been placed,
The optical cavity (10)
A second set (40) of quantum wells (41, 42, 43, 44, 45) arranged outside the direct range of the electrical injection means (31, 32, 33);
The second set (40) is such that at least one of their electronic resonances is in a strongly coupled system with the exciton-polariton mixed mode of the optical cavity (10). (20) arranged in relation to the quantum well (21, 22),
Light (2) radiation system (1) characterized in that. The light (2) is emitted in the form of a monochromatic light beam having directivity,
System (1) according to claim 1, characterized in that. The first set (20) includes a number of quantum wells (21, 22) substantially less than the number of quantum wells (41, 42, 43, 44, 45) of the second set (40). Out
System (1) according to claim 1 or 2, characterized in that. The quantum wells (21, 22, 41, 42, 43, 44, 45) of the first set (20) and the second set (40) are the same.
System (1) according to any one of claims 1 to 3, characterized in that. The optical cavity (10)
A bottom reflector (11) and a top reflector (12) disposed at the lower and upper ends of the optical cavity (10), respectively.
With
The upper reflector (12) is transmissive so that the light (2) emitted by the system (1) passes through the upper reflector (12),
System (1) according to any one of the preceding claims, characterized in that. The reflectors (11, 12) of the optical cavity (10) are Bragg reflectors,
System (1) according to claim 5, characterized in that. The optical cavity (10) includes a P-type doped region (13) and an N-type doped region (15).
System (1) according to any one of claims 1 to 6, characterized in that. The optical cavity (10) includes an undoped gap region (14) disposed between regions (13, 15) of the optical cavity (10) doped N-type and P-type, respectively. Yes,
System (1) according to claim 7, characterized in that. The quantum wells (21, 22) of the first set (20) are disposed between the gap region (14) and the P-type doped region (15) of the optical cavity (10).
System (1) according to claim 8, characterized in that. The quantum wells (41, 42, 43, 44, 45) of the second set (40) are formed between the N-type doped region (13) of the optical cavity (10) and the bottom reflector (11). Arranged between,
System (1) according to any of claims 7 to 9, which is dependent on claim 5 or 6, characterized in that. The means of injection (31, 32, 33) includes at least one pair (31a, 32a) of electrical contacts connected to a current supply (33).
System (1) according to any of claims 1 to 10, characterized in that. The contacts (31a) of one pair (31a, 32a) of the electrical contacts of the means (31, 32, 33) of injection are fixed to the N-type doped region (13) and the other contacts (32a) are Fixed to the P-type doped region (15),
System (1) according to claim 11, which is dependent on any one of claims 7 to 10, characterized in that. The optical cavity (10) is deposited on the substrate (3),
System (1) according to any of the preceding claims, characterized in that. The optical cavity (10) is a plane,
System (1) according to any of the preceding claims, characterized in that The optical cavity (10) is arranged such that the light (2) emitted by the system (1) is perpendicular to the transmissive reflector (12) of the optical cavity (10). ing,
15. System (1) according to any of the preceding claims, characterized in that The quantum wells (21, 22, 41, 42, 43, 44, 45) of the first group (20) and the second group (40) are made of a material composed of a gallium nitride group.
System (1) according to any of the preceding claims, characterized in that

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